I was on A/P for 3 months, changed to READY from Aug 15 to Sep 01, now it is again A/p, i emailed and asked about READY status they said ready means you are at final stage of administrative processing.
I think that is a slightly confusing response. So -
without wanting to get you too excited, because I am reading between the lines to some extent - here is what I think it means (and Susie alluded to the same thing above).
AP is a period of background checks. When those background checks have cleared, the AP is effectively finished. I think some have seen the status update from AP to READY, and that is most likely the signal that AP has ended. Of course - the case could be approvable or refused.
If the case is going to be denied, based on the background check, the update to refused could happen immediately - and IF the embassy is diligent about updating CEAC, that is what you would see - REFUSED.
If the case is going to be approved though, the embassy has to do a bit more work. They have to check with KCC that there is still a visa slot available. In a busy or oversubscribed year, that is a risk, this year - I don't think it is much of a risk at all. They also have to check that the medical is still valid and will give some reasonable window of time for the expiry date of the visa (because the visa expiry is based on the medical date PLUS 6 months).
Now - once those things are checked, they may ask for the passport if they don't already have it. It is possible they might ask for the passport while they are waiting for KCC to re-assign a visa slot.
If they have the passport, the visa slot, and the medical they can approve the case print the visa. I suspect that during that time they typically mark the case in AP again (so the READY gets updated back to AP. However, in most cases this AP status then changes to ISSUED about 1 to 3 working days later. This brief AP is seen on most cases that were approved at interview also (and it freaks people out).
So - that is why Susie said she suspects it is good news....